Azo dyestuff intermediates



. Patented Oct. 19, 1943 I a 2,332,388 f AZO DYESTUFF INTERMEDTATES Neil Mitchill Mackenzi signor to American e, Bound Brook, N. J., as- Cyanamid. Company, New

I York, N. Y., a corporation of Maine No Drawing. Original application June 7, 1941,

Serial No. 397,086. Di tion August 25, 1942,, S

7 Claims.

Thisinvention relates to sulfonic acid derivatives of acet'oacetic amides and to a method for preparing these compounds which have the fol-v lowing general formula:

CI-IsCOCI-IizCONI-IRX in which R is a saturated organic radical, X is a radical included in the group consisting of SOaH and its salts.

The products of the present invention may be prepared by reacting diketene with saturated amino sulfonic acids. It is known that in ma y reactions amino sulfonic acids do not behave like other amines and are, rather, internal salts or hybrid ions and it is therefore surprising that amino sulfonic acids can be readily reacted with diketene to give corresponding sulfonic acid derivatives of acetoacetic amides.

The reaction is carried out preferably in aqueous medium and the pH depends upon the specific compound to be reacted, although the preferred pH range is 4'to 7 since at a lower pH most of the amino sulfonic acids are not suificiently soluble.

and at a higher pH the yield is usually lower. In most cases room temperature is suitable although a temperature of 40-50 C. is preferred if it is desirable to increase the solubility of the amino sul-- fonic acid. The reactions are slightly exothermic and in some cases cooling of the reaction is advisable.

As examples of suitable aminosulfonic acids which may be reacted with diketene to give the sulfonic acid derivatives of the corresponding acetoacetic amide there may be mentionedv taurine, 1-amino-propane-2-su1fonic acid, 2- amino-Z-methyl-propane sulfonic acid, amino cyclohexane sulfonic acid, amino methane sulfonic acid.

Most of the products of this invention are very 4o soluble in water and in most cases it is necessary to evaporate the solution in order to isolate the compound, while in som cases the products may be salted out. If the compounds are to be used as coupling components in preparing azodyes it is not necessary to effect their isolation as any byproducts present do not enter into the coupling.

These intermediates are useful as coupling components for making azo dyes derived from acetoacetic amides and having sulfonic groups in the substituent of the amide radical. Of particular interest are those azodyes that are obtained from diazo components having in the orthoposition to the azo group a group enhancing complex formation with heavy metals. Such azo dyes maybe vided and this applicaerial N0. 456,269

converted into metallized dyes which are very valuable for dyeing wool. I

The invention is illustrated but not limited by the following examples in which the parts are given by weight.

Example 1v 12.5 parts of l-aminoethane-Z-sulfonic acid are added to a solution of 1.0 part of crystalline sodium acetate in 55 parts of water and stirred to a] smooth slurry. Then 9.8 parts of diketene are added over a period of seven hours during good stirring at 20-25 C. During the addition of diketene, the pH is held at 5-7 by the continuous addition of 10% sodium carbonate solution. At the end of the reaction the 1-aminoethane-2-su1- fonic acid disappears and a clear solution is formed. This solution can be used directly in the manufacture of azo dyes, or the new product can be isolated by evaporation. This new product may be represented by the following formula:

CH3 COCI-IzCONHCHzCHzSOsNt Emample 2 By the method outlined in Example l diketene will react with amino-methane sulfonic acid (obtained from formaldehyde bisulfite and ammonia as described by F. Raschig and W. Prahl in Justus Liebigs Annalen der Chemie, volume 448, page 265) to forma Water soluble sulfonic acid which, in the form of its sodium salt has the following structure:

CHsCOCHzCONHCHaSOsNa It is valuable as an intermediate for the preparation of azo dyestufis.

This application is a division of my copending application Serial No. 397,086, filed June 7, 1941.

What I claim is: 1. A method for preparing compounds corresponding to the formula I CH3COCH2CONHRX I in which R is a saturated hydrocarbon radical and X is-a member of the group consisting of SOsH and its salts by reacting diketene with a 1 compound included in the group consisting of the I corresponding amino sulfonic acids and their salts.

2. A method according to claim 1 in which'the reaction is carried. out in an aqueous medium at a pH of between 3 and 9. p v p 3. New products having the following formula:

, onscocnzcoumsx in which R is a saturated hydrocarbon radical,

and X is a member of the'group consisting of 6. New products having the following formula: 803K and its salts.

4. New products according to claim 3 in which CHZCOCHZCONHCHZSON R ls a saturated aliphatic hydrocarbon radical. in which Y is 1 5. New products having the following formula: 5 New p o s having e following formula:

in whichYis a cation.

in which Rfis alkylenel and T15 a catioh. NEIL mrrcrmm MACKENZIE. 

